Let the original price be x. After a 25% discount, the price is x - 0.25x = 0.75x. So, 0.75x = 30, thus x = 40.

The correct form is 'was' because 'neither/nor' takes a singular verb.

4 books at $15 each costs 4 * 15 = $60.

At 60 miles per hour, in 3 hours the car will travel 60 * 3 = 180 miles.

The car travels 60 miles per hour. In 3 hours, it will travel 60 * 3 = 180 miles.

If 2 cups are for 4 servings, then for 10 servings it requires (2/4) * 10 = 5 cups.

Area = length * width = 10 * 5 = 50 square units.

The train travels for 4 hours, so it will arrive at 3 PM + 4 hours = 7 PM.

The train travels for 2 hours at 80 miles per hour, so it will cover 80 * 2 = 160 miles.

Time = distance/speed = 240/80 = 3 hours. So, it will arrive at 6 PM.

2.5 hours after 3 PM is 5:30 PM.

12% of 150 is 0.12 * 150 = 18.

'Bite the bullet' means to take a risk or face a difficult situation.

'Burn the midnight oil' means to work late into the night, indicating being very busy.

The correct sentence is 'She goes to the store.'